1. Field of the Invention
The invention relates to a tool for creating a flat bottom hole into a stock material.
2. Background
For many applications, it may be desirable to form a hole in a work piece substrate which terminates in a flat bottom surface. Many types of cutting tools and drilling systems have been developed for creating holes having flat bottoms.
Some cutting tools in the prior art utilize one type of drill for starting such a hole, and then using a second metal cutting tool to produce the desired flat bottom in the hole.
Prior art cutting tools that were designed to cut flat bottomed holes have various deficiencies. Some flat bottomed hole drills had cutting edge designs that could form a flat bottom hole, but these drill configurations resulted in a weakened area, point or line where these prior art drills would occasionally break or fracture. In other prior art flat bottom cutting drills, the drills were configured such that chips from the drilling process were not formed efficiently, causing excessive wear and chip control problems. Additionally, the nature of these cutting edges resulted in high cutting forces, specifically in thrust.